8 Points to Note When Welding Square and Rectangular Tubes

When welding square and rectangular tubes, the following eight points should be noted:

 

 

(I) Before igniting the welding torch, check the airtightness of all gas valves and connections. If any leaks are found, repair them.

 

(II) Ensure that all gas passages of the welding equipment are free of oil contamination to prevent oxygen from igniting and exploding upon contact with grease.

 

(III) If backfire is detected, immediately close the acetylene valve on the powder torch and immediately close the main valve on the wire torch. This will quickly extinguish the backfire within the torch. Wait a moment, then open the main valve again to blow out any remaining soot before igniting. Use a lighter to ignite the torch; never use a cigarette butt, as this can easily burn your hands.

 

(IV) When not in use, the torch should be hung up along with the hose or placed in a box to prevent dust and impurities from entering and affecting its use.

 

(V) The injection suction performance of the welding square and rectangular tubes must be checked before use. During the check, connect the oxygen pipe, open the acetylene valve and the oxygen valve, and gently touch the acetylene inlet of the spray gun with your finger. If you feel a suction force, the injection suction is normal, and it can be used. Otherwise, it is abnormal and should be checked and repaired.

 

(VI) When welding square and rectangular tubes, it is strictly forbidden to block the spray gun nozzle with your hand or other objects while the oxygen valve and acetylene valve are open simultaneously, to prevent oxygen backflow into the acetylene generator.

 

(VII) It is strictly forbidden to lay a burning spray gun haphazardly on the ground or other objects. The nozzle mating parts must not be rough; otherwise, backfire or even "flare-out" may occur during use.

 

(VIII) When welding square and rectangular tubes, the transmission parts should be kept lubricated frequently; a thin layer of molybdenum disulfide grease can be added.

 

Conclusion: Welding square and rectangular tubes is a highly technical and standardized professional operation. By strictly adhering to these eight key points and combining them with scientific equipment management and personnel training, enterprises can not only significantly improve welding quality and production efficiency, but also build a robust safety barrier. With the development of automated welding technology, these fundamental standards remain irreplaceable core principles in human-machine collaboration and deserve an in-depth understanding and consistent practice from every welding professional.